Store instructions do not modify register values and therefore it's safe
to form a store pair even if the source register has been read in between
the two store instructions.
Previously, the read of w1 (see below) prevented the formation of a stp.
str w0, [x2]
ldr w8, [x2, #8]
add w0, w8, w1
str w1, [x2, #4]
ret
We now generate the following code.
stp w0, w1, [x2]
ldr w8, [x2, #8]
add w0, w8, w1
ret
All correctness tests with -Ofast on A57 with Spec200x and EEMBC pass.
Performance results for SPEC2K were within noise.
llvm-svn: 239432
This was previously returning int. However there are no negative opcode
numbers and more importantly this was needlessly different from
MCInstrDesc::getOpcode() (which even is the value returned here) and
SDValue::getOpcode()/SDNode::getOpcode().
llvm-svn: 237611
Teach the load store optimizer how to sign extend a result of a load pair when
it helps creating more pairs.
The rational is that loads are more expensive than sign extensions, so if we
gather some in one instruction this is better!
<rdar://problem/20072968>
llvm-svn: 231527
This patch adds the missing LD[U]RSW variants to the load store optimizer, so
that we generate LDPSW when possible.
<rdar://problem/19583480>
llvm-svn: 226978
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.
"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.
This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.
llvm-svn: 209577
Pete Cooper